5.4.2 Configuring the CLI

https://docs.aws.amazon.com/cli/latest/userguide/cli-chap-configure.html

This section explains how to configure the settings that the AWS Command Line Interface (AWS CLI) uses to interact with AWS. These include:

• your security credentials,
• the default output format, and
• the default AWS Region.

AWS requires that all incoming requests are cryptographically signed. The AWS CLI does this for you. The "signature" includes a date/time stamp. Therefore, you must ensure that your computer’s date and time are set correctly. If you don’t, and the date/time in the signature is too far off of the date/time recognized by the AWS service, AWS rejects the request.